Method

Heat the oven to 180C (gas mark 4). Grease a shallow 20x30cm
(8x12in) cake tin and line the base and sides with baking paper,
extending the paper 5cm (2in) above the tin.

Place the oil, sugar, orange zest and a pinch of salt in an
electric mixer bowl and mix on a medium speed until well beaten.
Reduce the speed of the mixer and gradually add the
eggs.

Sift over the flour and gently fold in with a large metal spoon
until smooth. Fold in the grated carrot and half the chopped
pistachio nuts. Spoon tbe batter into the tin and smooth the
surface.

Bake for 35-40 mins, or until golden and firm to the touch.
Cool in the tin for about 10 mins, then, with the help of the
overhanging baking paper, turn the cake out onto a wire rack to
cool completely. To make the icing, use a handheld electric beater
to mix together all the ingredients until smooth and light. Spread
over the top of the cake and sprinkle with the remaining nuts. Cut
into 12 squares.